Morishita Tetsuya
Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Phys Rev Lett. 2004 Jul 30;93(5):055503. doi: 10.1103/PhysRevLett.93.055503.
Polyamorphic transformations of silicon have been investigated by constant-pressure first-principles molecular-dynamics simulations. By pressurizing a normal amorphous Si with tetrahedral coordination, a new high density amorphous (HDA) form that has a strong resemblance to HDA water is obtained. We find that the HDA form can be also obtained through vitrification of liquid Si under pressure. Both HDA and liquid Si contain deformed tetrahedral configurations with interstitial atoms. These findings indicate that HDA Si is directly connected with liquid Si, which is of particular importance in understanding phase relations of polyamorphs of Si.
通过恒压第一性原理分子动力学模拟研究了硅的多晶型转变。通过对具有四面体配位的普通非晶硅施压，获得了一种与高密度非晶水非常相似的新型高密度非晶（HDA）形式。我们发现，HDA形式也可以通过在压力下将液态硅玻璃化得到。HDA和液态硅都包含带有间隙原子的变形四面体构型。这些发现表明，HDA硅与液态硅直接相关，这对于理解硅的多晶型物的相关系尤为重要。
